Views: 1 Author: Site Editor Publish Time: 2025-06-10 Origin: Site
On May 19, 2025, our long-standing client in Singapore sent us an inquiry for ASTM A234 WPB carbon steel butt weld caps. By May 26, we had received their purchase order and successfully completed production within 5 days. Some information in the client's order was incomplete, but our salesperson quickly supplemented the details, sent them to the client for confirmation, and received their approval.
Shanghai Zhucheng Pipe Fitting Manufacturing Co., Ltd.is a professional enterprise specializing in the production and processing of pipes and pipe fittings. Our products are primarily used in various sectors, including chemical, petroleum, natural gas, water conservancy, power, and offshore engineering.
Our main product offerings include:
Seamless pipes and welded pipes of various sizes.
High-pressure forged fittings.
We manufacture these products from a wide range of materials, such as carbon steel, stainless steel, alloy steel, low-temperature steel, duplex steel, and nickel-based alloys.
Wall Thickness: Measure at multiple points to ensure that the wall thickness meets the Schedule grade requirements of the order and is within the tolerance range.
Outside Diameter (OD): The outer diameter of the butt-weld groove at both ends of the pipe cap should comply with ASME B16.9.
Length (Length E): The overall height or length of the pipe cap should comply with ASME B16.9.
Length (Length E)
Wall Thickness
Outside Diameter (OD)
End protection: The butt weld groove end of the pipe cap is a critical part and requires special protection to prevent damage.
Plastic or wooden groove protection cover: Plastic caps or wooden protection rings are usually put on the groove to prevent the groove from being damaged during transportation.
Filler: For larger tube caps, foam or other cushioning materials may be placed inside to prevent internal impact during transportation.
Wooden Crates/Cases:
Provides the best protection, can withstand heavy pressure and impact, suitable for long-distance transportation, sea transportation or occasions with high requirements for product protection.
Standard | ASME B16.9 |
Size Range | 1/2” - 48” |
Thickness Schedule | SCH 10, SCH 40, SCH 80, SCH 160, XXS |
Carbon Steel Material | ASTM A234 WPB/WPC |
ASTM A234: This is a standard issued by the American Society for Testing and Materials (ASTM), which specifies the materials, chemical composition, mechanical properties, heat treatment requirements, manufacturing process, inspection methods and markings for the manufacture of pipe fittings. It ensures that pipe fittings can operate safely and reliably under specific temperature and pressure conditions.
WPB: This is a specific grade within ASTM A234.
- W stands for "weldable" (meaning suitable for welding).
- P stands for "pressure" (indicating its use in pressure piping).
- B refers to its minimum yield strength, which is typically 35 ksi (240 MPa), and minimum tensile strength of 60 ksi (415 MPa).
Butt weld connection: This is one of the strongest and most reliable connection methods in the pipeline system, suitable for severe working conditions of high pressure, high temperature and low temperature. It ensures smooth flow inside the pipeline system, reduces turbulence and pressure loss, and minimizes corrosion and wear.
Caps: Pipe caps are pipe accessories that are mainly used to close the end of a pipe to terminate the flow of fluid in a pipe system. It acts as a seal to prevent leakage of liquid or gas and protect the inside of the pipe from the intrusion of dust, moisture or other external factors.
CHEMICAL | LIMITS | C | Mn | P | S | Si | Cr | Mo | Ni | Cu | Cb | V |
ASTM A234 WPB | MIN | 0.29 | 0.10 | |||||||||
MAX | 0.30 | 1.06 | 0.050 | 0.058 | 0.40 | 0.15 | 0.40 | 0.40 | / | 0.08 |
MATERIAL | T.S (MPA) | Y.S (MPA) | EL % | R/A % | HARDNESS |
ASTM A234 WPB | 415 min | 240 min | 22 min | 30 min | 197 max |
DN | NPS | OD | E | E1 |
15 | 1/2 | 21.3 | 25 | 25 |
20 | 3/4 | 26.7 | 25 | 25 |
25 | 1 | 33.4 | 38 | 38 |
32 | 11/4 | 42.2 | 38 | 38 |
40 | 11/2 | 48.3 | 38 | 38 |
50 | 2 | 60.3 | 38 | 44 |
65 | 21/2 | 73.0 | 38 | 51 |
80 | 3 | 88.9 | 51 | 64 |
90 | 31/2 | 101.6 | 64 | 76 |
100 | 4 | 114.3 | 64 | 76 |
125 | 5 | 141.3 | 76 | 89 |
150 | 6 | 168.3 | 89 | 102 |
200 | 8 | 219.1 | 102 | 127 |
250 | 10 | 273.0 | 127 | 152 |
300 | 12 | 323.8 | 152 | 178 |
350 | 14 | 355.6 | 165 | 191 |
400 | 16 | 406.4 | 178 | 203 |
450 | 18 | 457.0 | 203 | 229 |
500 | 20 | 508.0 | 229 | 254 |
550 | 22 | 559.0 | 254 | 254 |
600 | 24 | 610.0 | 267 | 305 |
650 | 26 | 660.0 | 267 | --- |
700 | 28 | 711.0 | 267 | --- |
750 | 30 | 762.0 | 267 | --- |
800 | 32 | 813.0 | 267 | --- |
850 | 34 | 864.0 | 267 | --- |
900 | 36 | 914.0 | 267 | --- |
950 | 38 | 965.0 | 305 | --- |
1000 | 40 | 1016.0 | 305 | --- |
1050 | 42 | 1067.0 | 305 | --- |
1100 | 44 | 1118.0 | 343 | --- |
1150 | 46 | 1168.0 | 343 | --- |
1200 | 48 | 1219.0 | 343 | --- |
There are mainly tow ways for buttweld fittings manufacturing: cold drawn and hot forming.
1. Material preparing
2. Cutting: Cutting pipes or plate into certain shape or length
3. Forming: Form materials into shapes such as BW Pipe cap, 90 degree elbow, reducing tee. Cold drawn product will be formed directly into specific shape by hammers, mechanical presses or upsetters. Hot forming process will heating the material first and then form it.
4. Heat Treatment: It is the process of heating and cooling metals to change the microstructure and to bring out the physical and mechanical properties that make metals more desirable.
5. Machining: This process is using sharp cutting tools to trim shapes and prepare ends.
6. Inspection and Test: In accordance to standards inspect the size, material and appearance.
7. Coating as requirement
Oil and Gas: Used in pipelines, refineries, and processing facilities to cap off lines or temporary connections.
Chemical and Petrochemical Plants: For sealing pipes carrying various chemicals, often in corrosive or high-temperature environments.
Power Generation: In power plants for steam lines, water systems, and other utility piping.
Water Treatment and Supply: For municipal water infrastructure, wastewater treatment plants, and industrial water systems.
HVAC Systems: In larger industrial heating, ventilation, and air conditioning systems.
Shipbuilding: For various piping systems within marine vessels.
General Industrial Piping: Wherever a permanent and strong seal is needed at the end of a carbon steel pipeline.
